09-09-2013, 05:48 AM
focus accuracy and speed is not only determined by the lens but also by the camera. No offense, but don't expect miracles from your D7000.
I was going to suggest a Sigma 17-70/2.8-4, that's the one of the new Contemporary line. There's a dock connector available from Sigma to adjust speed, accuracy (meaning, find a good compromise between those parameters) and also adjust focus. Also, expect no miracles - this device will get the last 2-5% of accuracy but doesn't upgrade a comparably cheap lens into an optical phenomena.
From the ww lenses I only know the Sigma 10-20/3.5, used that on Pentax quite a while and found it great. And it's fixed aperture and still 1/4 lower in price than Nikon 10-24/3.5-4.5
I was going to suggest a Sigma 17-70/2.8-4, that's the one of the new Contemporary line. There's a dock connector available from Sigma to adjust speed, accuracy (meaning, find a good compromise between those parameters) and also adjust focus. Also, expect no miracles - this device will get the last 2-5% of accuracy but doesn't upgrade a comparably cheap lens into an optical phenomena.
From the ww lenses I only know the Sigma 10-20/3.5, used that on Pentax quite a while and found it great. And it's fixed aperture and still 1/4 lower in price than Nikon 10-24/3.5-4.5